All else — unless you've somehow snuck a script out from under the security lockdown at Lucasfilm or J.J. Abrams' television production company Bad Robot — is speculation. To give us even fewer handholds, Lucasfilm announced on Friday that the decades of books and comics that told stories following Return of the Jedi are no longer considered canon — which means they'll have no bearing on the forthcoming movie, to be released in December 2015.

Elements from those stories may still be used, but completely out of their original contexts. (Sorry, fans of Grand Admiral Thrawn and Mara Jade.)

That said, Tuesday's casting announcement gives us something to work with. Given the strengths of each actor, the types of characters they've portrayed in the past and their ages relative to the returning original cast, we can indulge in some informed speculation. Let's start with the elder statesman of the cast.

Max Von Sydow

The 85-year old multilingual Swedish legend has an unparalleled range of credits, stretching from the knight in Ingmar Bergman's Seventh Seal and Jesus Christ in The Greatest Story Ever Told to Ming the Merciless, Emperor of the Universe in Flash Gordon. He also has a history of playing the old mentor figure who turns out to be the bad guy, as in Minority Report. In theory, that makes him the most enigmatic of cast members.

Here he is in his most recent major-movie role, a silent renter in Extremely Loud and Incredibly Close:

But given that Von Sydow is more than 20 years older than Ford, Hamill and Fisher, that limits the kind of roles he can play in Episode VII. After all, we saw the Jedi wiped out (Obi-Wan Kenobi and Yoda excepted) in Episode III, 20 years before the original Star Wars. So it's unlikely we'll see Von Sydow as a crusty old Jedi in the Kenobi mold, and far more likely he'll be a crusty old Imperial officer in whatever remains of the Galactic Empire 30 years after its second Death Star defeat — or possibly a new Sith Lord in the style of Emperor Palpatine or Count Dooku.

That said, there is one old Jedi Von Sydow could play, given the timeline: Kanan, the renegade "cowboy Jedi" of Star Wars Rebels, the animated Disney XD show coming this fall, and set between Episode III and IV. The age is about right, and their faces are similar. Rebels will be canon, after all. Introducing an animated character in 2014, then revealing the live-action version much later in life the following year, would be just the kind of audacious meta-story point we know director Abrams loves.

Daisy Ridley

The mystery lady of Episode VII, Daisy Ridley

Image: Daisy Ridley/IMDB

At the other end of the experience spectrum is unknown British actor Daisy Ridley, whose only appearance on U.S. screens so far has been one episode of the PBS show Mr. Selfridge. Fans have already noted the fact that she's pictured sitting between Harrison Ford and Carrie Fisher in the casting photo released on StarWars.com, deep in conversation with Fisher, and speculated that this must mean she's playing Han and Leia's daughter.

Certainly, Ridley has the feistiness, charm and looks that you'd expect from any child of the Solo and Skywalker lines. She also looks a lot like Natalie Portman's Senator Amidala, who would be her character's grandmother if Leia's her mother. Ridley also bears a strong resemblance to the description of Jaina Solo, daughter of Han and Leia in the books. (Again, the book history may be wiped over, but Abrams and co-writer Lawrence Kasdan have the freedom to pick and choose what stays.)

Then again, Ridley may well be the 17-year-old "Rachel" character mentioned in the Episode VII casting call, who was said to be "quite young when she lost her parents ... forced to make her way in a dangerous town." Or that may simply have been an approximation of the kind of character Abrams was looking for. Your speculation may vary.

Andy Serkis

Serkis is a talented actor in his own right — he played rocker Ian Dury in 2010's Sex and Drugs and Rock and Roll, for instance. But you almost certainly don't hire Serkis for a space-fantasy epic unless you're thinking of his astonishing motion-capture work that brought life to CGI characters such as Gollum in the Lord of the Rings trilogy or Caesar in Rise of the Planet of the Apes.

Motion capture and CGI means Serkis could play literally any of the hundreds of alien races already known to exist in the Star Wars universe, from Aqualish (e.g. the guy who gets his arm sliced off in the Mos Eisley Cantina) to Zabrak (e.g. Darth Maul). One species he's unlikely to play, however, is Gungan. We saw more than enough Jar Jar Binks in the prequels, and Lucasfilm sans Lucas is likely to steer clear of that controversial, oft-annoying species.

Adam Driver

Best known for his role in HBO's Girls, Driver has apparently been in the casting crosshairs for some time. We first heard rumors of his involvement last year, and he's about the only actor to feature prominently in those rumors, and still actually nab a part in Episode VII. Variety reported in February that Driver was close to signing on as the main villain of the movie — but even reports from Hollywood's top trades need to be taken with a pinch of salt when you're talking Episode VII.

Still, Driver would clearly make a compelling young bad guy. If Lucasfilm hadn't wiped over the novels' chronology, we'd say he's a shoo-in to play Jacen Solo, the son of Han and Leia who turns to the dark side and becomes Darth Caedus. That's still a strong possibility even without the novels, of course. After all, someone is going to have to turn to the dark side for the legendary war of Jedi and Sith — the prime mover of the Star Wars universe — to continue.

Domhnall Gleeson

Born the year Return of the Jedi came out, Gleeson (whose first name is pronounced Doe-nall) has a history of playing straitlaced, sympathetic sons. He was the hardworking and rather humorless elder Weasley child in the Harry Potter movies. And in the Richard Curtis film About Time, Gleeson plays the son of Bill Nighy who is suddenly informed he can travel in the fourth dimension:

All of which would make him perfect for the role of Luke's son Ben Skywalker, who battles his cousin Darth Caedus — if, again, the continuity of the books had not been wiped over. And no director of a major space franchise would ever fake out the audience on whether a given character was appearing in a movie — right, J.J. Abrams?

John Boyega

Another British actor largely unknown to American audiences, Boyega got some practice fighting aliens in last year's Attack the Block, a well-received alien-invasion horror film set in a tower block in south London. You can see Boyega talk about his character, Moses, in the promotional film, above.

If Ridley is "Rachel" from the casting call for teenage characters, then it's likely Boyega is "Thomas" — described as a man who has "grown up without a father's influence" who can "appreciate the absurdities in life and understands you can't take life too seriously." We'd say fighting CGI aliens alongside a long-haired Nick Frost certainly qualifies Boyega for the latter.

Oscar Isaac

We doubt there's much call for folk musicians in a galaxy far, far away. But Isaac, born Óscar Isaac Hernández and best known as the star of Inside Llewyn Davis, has a few more strings to his bow. He played King John in the 2010 Ridley Scott version of Robin Hood and Joseph in the biblical drama The Nativity Story.

This all suggests Isaac is drawn to playing tragic, impatient or imprudent figures — traits that tend to lead to the dark side in the Star Wars universe. Is Isaac on the Sith side? We'll find out, as we'll find out the truth of all this speculation in about 18 months time. Patience you must have, young Jedi.

Chris Taylor is the author ofHow Star Wars Conquered the Universe, the first complete history of the Star Wars franchise and its fandom. The book releases September 30 and is available for pre-order here.

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